Each year 48 million people are sickened with a foodborne illness due to fruit and vegetable production, commonly called “food poisoning.” Children and the elderly are more susceptible than adults are. Home, school and community gardens are at risk. Most illnesses that are linked to home and other gardens result from the use of raw manure. Improperly brewed compost teas are another potential source of pathogens.
There is a myth that washing or peeling produce is sufficient to remove pathogens. However, prevention of microbial contamination in the first place is the most important food safety element, even at home. The National Organic Program specifies that if manure is not composted properly prior to use in a garden or farm, it must be tilled into the soil at least 120 days before the harvest of a food crop that touches the soil, such as lettuce. For crops such as corn that do not contact the soil, the lead-time is 90 days. Alternately, you can compost manure to at least 131 degrees to kill the disease-causing organisms or amend with manure in the fall long before you intend to plant. To be safe, not even composted manure is recommended for school gardens.
Another myth is that organic produce is more likely to cause foodborne illness. However, both conventional and organic growers use manure as a fertilizer and while manure use on certified organic farms is strictly regulated, there are no rules for use of manure in conventional operations.
A third myth is that if you don’t apply manure to your garden, you don’t have to worry about pathogens. Consider that rabbits, birds, rodents and other critters may run through your garden contaminating it; and that many pathogenic organisms actually live in soil naturally.
Most foods are safer if they are washed, dried and stored in the refrigerator after harvest. The exceptions are tomatoes, potatoes, berries, which should be washed right before you eat them. Produce that touches the soil such as cantaloupes should be scrubbed with a vegetable brush and dried completely before refrigerating.
Water is the most likely vehicle to put pathogens in contact with produce. Municipal water is safe and drip irrigation minimizes contact with edible parts. Well water should be tested for coliform and E. coli bacteria before being used on edibles.
Wear gloves when harvesting. Wash hands before and after harvesting. Sanitize tools before and after use with no more than one tablespoon of bleach to one gallon of water.
University of Nevada Cooperative Extension Grow Your Own class on August 5, from 2:30 to 4:30 p.m., will cover “What’s Wrong with My Plant.” Call 887-2252 for more information.